Numerous proposals have been made for avoiding communication of disease through sharing of hydrodermic needles or syringes. For instance, one of the leading causes of the spread of AIDS (Acquired Immune Deficiency Syndrome) is through intravenous injection of drugs through the use and reuse of needles by different persons. Furthermore, at medical institutions it is important to insure that an injection is not administered from a previously used syringe.
Previously, proposals have been made to construct a non-reusable syringe but none to the best of my knowledge has proven to be commercially acceptable or recognized for use by the medical profession. Among other problems in the past design of non-reusable syringes are the relatively high cost of construction and assembly, reliability in use and necessity of education of the user. Of the proposals made in the past, one approach has been to use a ratchet arrangement which will permit the plunger assembly to be advanced forwardly through the barrel of the syringe in forcing the material to be dispensed through a hypodermic needle at one end of the barrel but will not allow the plunger to be retracted or withdrawn through the barrel in order to refill the syringe. Representative of that approach are U.S. Pat. Nos. 4,731,068 to Hesse and 4,449,703 to Butterfield. Another approach taken in the past has been provision for the combination of a threaded plunger stem and a spiral complementary groove along the interior of a sleeve element which fits into the barrel of a syringe and representative of that approach is the Swiss Patent No. 340,314. However, this design is not capable of preventing reloading or reuse of the syringe. Other representative patents in this field are U.S. Pat. Nos. 3,820,652 to Thackston and 4,781,684 to Trenner.